[prog] Yacc - double errors

[Sue Stones]

On Tue, 10 Feb 2004 11:01 am, Jimen Ching wrote:
> On Mon, 9 Feb 2004, Sue Stones wrote:
> >---------------------------------------
> >end_statement:  END SEMI { fprintf(stdout, "end;\n"); }
> >
> >        |       END  error      {
> >
> >                        errorstr = strdup("Missing semicolon after
> > \"end\""); yyerror(errorstr); }
> >        ;
> >---------------------------------------
>
> Exactly what errors are you seeing?
>
> --jc

Well I have rewritten it a number of times, and seen diferent things, 
sometimes I get the line number followed by "syntax error" the first time, 
then the same line number followed by my own error.  Sometimes I have "syntax 
error" twice for the same line.  sometimes I have "Missing semicolon" twice 
for each error.  

The error count is double what it should be too.  Also I am getting an error 
at the end of the file, even when I shouldn't be.

The impression I get is that it is calling the yyerror routine twice, once 
automaticaly, and once when I call it.  But there is nothing in the 
documentation that I have that mentions how this miht be happening.

Somewhere there was a mention of errok and double errors, but it doens't seem 
to make any diference whether I use errok or not.

Here is an example:
---------------------------------

plus.b:1: syntax error
plus.b:1: Missing semicolon after 'do'
plus.b:3: syntax error
3 errors
--------------------------------
input:
------
while name2 <> 0 do
        incr name1;
        decr name2;
end;
incr name2;
---------------------------------

sue